hydrogen

From Wiktionary

[change] Pronunciation

• IPA: /ˈhaɪdrɘdʒɘn/
•  Audio (US)^{help, file}

[change] Noun

Singular hydrogen

Plural hydrogens

1. (uncountable) The lightest chemical element (symbol H) with an atomic number of 1.

   Hydrogen gas is highly flammable.

2. (countable) A hydrogen bomb (H-bomb), or fusion bomb, is a nuclear weapon.

The Periodic Table
H																															He
Li	Be																									B	C	N	O	F	Ne
Na	Mg																									Al	Si	P	S	Cl	Ar
K	Ca															Sc	Ti	V	Cr	Mn	Fe	Co	Ni	Cu	Zn	Ga	Ge	As	Se	Br	Kr
Rb	Sr															Y	Zr	Nb	Mo	Tc	Ru	Rh	Pd	Ag	Cd	In	Sn	Sb	Te	I	Xe
Cs	Ba	La	Ce	Pr	Nd	Pm	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu	Hf	Ta	W	Re	Os	Ir	Pt	Au	Hg	Tl	Pb	Bi	Po	At	Rn
Fr	Ra	Ac	Th	Pa	U	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr	Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Uub	Uut	Uuq	Uup	Uuh	Uus	Uuo
alkali metals alkaline earth metals lanthanides Actinides Transition elements Other metals Metalloids Other nonmetals Halogens Noble gases